The present invention relates to railway locomotive brake control apparatus and particularly to such apparatus as affords the locomotive engineer the ability to selectively cut in or cut out the locomotive brake valve device.
One well-known locomotive brake valve device is the standard 26-C brake valve shown in Westinghouse Air Brake Co. instruction pamphlet G-g-5071-6. Basically, this brake valve device includes a regulating valve through which equalizing reservoir pressure is controlled by manipulation of the automatic brake valve handle and a relay valve that in turn controls the supply and exhaust of pneumatic pressure carried in the train brake pipe according to the effective equalizing reservoir pressure. In addition, there is further provided a manual selector valve having a cut-in position and a cut-out position, and a brake pipe cut-off valve, the latter of which can be conditioned to interrupt the supply and exhaust of brake pipe pressure by manually setting the selector valve in cut-out position. This permits the locomotive brake valve device to be disabled or cut out, by isolating it from the brake pipe, for the purpose of conducting brake pipe leakage tests, for multiple-unit operation, for hauling a locomotive "dead," for double-heading operation, etc.
Such an arrangement has given rise to an unauthorized operating procedure being employed by locomotive engineers during train movement, in which the selector valve is improperly moved to cut-out position to avoid a penalty brake application on trains having automatic safety control, overspeed and train control penalty systems. Manipulating the selector valve in such an unauthorized manner, in effect, disables the brake valve device.
Thus, an extremely dangerous situation is created not only from the standpoint of having the various safety protection systems ineffective due to the inability to achieve a penalty brake application, but also from the standpoint of having the normal operator control of the train brakes through the brake valve device ineffective during the time the selector valve is in cut-out position.